2d XiifeQtons for 'tanning 



equal upon an average to ten per cent, upon each more tlian 

 in the ufual way. 



A hide, to be properly tanned, muft have imbibed the 

 quantity of tanning neceflary to faturate it; and whether it 

 receive that quantity in one or in eighteen months, it can 

 make no difference in the quality of the leather, but a very 

 material one to the manufafturer. 



The opinion that fo many months were ncceffary to tan 

 hides, was founded on the clumfy and injudicious mode of 

 throwing the hides and bark together in the pits ; but this 

 opinion is now rapidly giving way, and probably will, with 

 your affirtance and that of other fcicntific men, be totally 

 exploded in lefs time than was hitherto required to tan a 

 hide. Tanners will be much indebted to you for your en- 

 deavours to undeceive them ; and the public, I think, mull 

 be ultimately benefited by the general adoption of this 

 proccfj. 



I am very refpeftfully, 

 Sir, 

 Your humble and obedient fervant, 

 Alexander Tilloch, Efg. William Desmond. 



Direilions for Tanning. 



AS that part of the preparation of hides and fkins, pr(y- 

 perly called tanning, confifts in impregnating and faturating 

 them with a principle obtained from tan, by which they 

 acquire ftrength and tirmnefs, preferve a fufficient flexibility, 

 and become indifToluble and incorruptible in water either hot 

 or cold ; fo the nature of this procefs is, ift, To afcertain, by 

 a fimple and certain criterion, fuch fubftances as contain the 

 faid principle : 2dlv, To extract it from them, to feparate it 

 from every other principle by which its effect might be im- 

 peded or countera(I:led, and to give it the degree of ftrength 

 neceffary for the intended purpofe : 3dly, To difpofe the hides 

 and fkins for the introdmSiion of this principle : and, 4thly, 

 To impregnate and faturate them completely with the fame 

 hi lefs than a tenth part of the time ufually employed in tan-, 

 iilng; all .which operations arc performed in the following 

 manner r 



Provide five vefTels, called Sigeflen, of any convenient 

 material.^ and dimenlion,-, with an aperture at the bottom of 

 each : let them be placed near each other, and elevated upon 

 liillages or othervvife, fo that a pail or other fmaller veffel 

 may be placed under them. Fill the digefters with tan, that 



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